Located on the southern end of Cibola National Wildlife Refuge about 20 miles south of Blythe, California, Hart Mine Marsh was initially created by historic overbank flood flows from the Colorado River.  With changes in the river system, including water operations and management, the dynamic processes that once maintained this marsh have been all but removed. Hart Mine Marsh has instead been managed by using drainage waters from the refuge’s agricultural fields. Until recently, the marsh had no outlet, resulting in poor water quality and highly saline areas mostly dominated by invasive saltcedar. 

By enhancing the ability to manage water on the site and by maintaining water levels and providing appropriate vegetation, suitable habitat for marsh species could be created in this location. So the Bureau of Reclamation and the U.S. Fish and Wildlife Service entered into a long-term agreement under the Lower Colorado River Multi-Species Conservation Program to reconstruct the area. The result will be a mosaic of marsh vegetation and open water. 

After restoration, approximately 255 acres of open water and marsh have returned to Hart Mine Marsh. This was accomplished by removing nonnative vegetation, and excavating and re-grading to provide areas for emergent marsh vegetation and permanent open water. In addition, water management was improved by adding a series of gated control structures, including outlet structures to allow for flexibility in water control on the site.

The work was completed in phases over 3 years, and completed in 2011. The resulting marsh is providing habitat for a number of resident and migrating bird species including the Yuma clapper rail and the least bittern.   In 2012, Hart Mine Marsh was awarded the U.S. Department of the Interior Partners in Conservation Award.

A fact sheet for this Conservation Area can be found here. Technical Reports for this Conservation Area can be found here.

Updated December 30, 2016

Cibola National Wildlife Refuge is located approximately 15 miles south of Blythe, California and includes lands managed by the U.S. Fish and Wildlife Service in the states of California and Arizona.   Hart Mine Marsh is approximately 5 miles south of the Refuge Headquarters in La Paz County, Arizona. The river forms the western boundary, from approximately river mile 91 to river mile 93.

The Conservation Area is located on a portion of the Refuge open to waterfowl hunting that allows public access, but only on designated roads and during certain hours.  Information on Cibola National Wildlife Refuge, including location, purpose, and regulations, can be found on their website at this link.

For specific information on the Conservation Area, please contact Terry Murphy, Restoration Group Manager, at (702) 293-8140 or via email at tmurphy@usbr.gov.

The image below shows a close up of the conservation area.

Each Conservation Area targets certain LCR MSCP covered and evaluation species habitats. Below, on the left, is a list of the LCR MSCP species in which habitat will be targeted for creation for in this particular conservation area. To the right is a list of LCR MSCP species that, through monitoring, have been found utilizing the conservation area.

Water management, including maintaining relatively constant marsh water levels during the marsh bird breeding season, and through the delivery of raw Colorado River water and returns flows from the Refuge’s farming operations, are the primary management activities.  Invasive and non-native vegetation control, particularly while the marsh is developing, is a key component of the project.

Monitoring of abiotic parameters, such as water quality, soil conditions, and site hydrology are conducted.  Presence/absence surveys for marsh birds began in 2011.

Bird Monitoring

Surveys for covered birds are conducted annually. Marsh bird surveys are conducted in March, April, and May at established points for California black rail, western least bittern, and Yuma clapper rail.

Insect Monitoring

Surveys are conducted for MacNeill’s sootywing annually to document presence of the species in the conservation area.

Acreage Map

This map shows the acreage for this area. You can click on the map for a larger view.

This gallery includes photos of this conservation area. If you require larger photos, please contact our webmaster Michelle Reilly at mreilly@usbr.gov.